The World Federation One Stop Fiqh

Ruling 203

If the blood of a human being, or of an animal whose blood gushes out when its jugular vein is cut, is sucked by an animal that is commonly known to have no blood, such that it may be absorbed in that animal’s body – like when a mosquito sucks blood from a human being or from an animal – then that blood is pure. This is called ‘transfer’. As for the blood that a leech sucks from a human being for the purposes of treatment, as it is not known whether or not that blood becomes part of its body, it is impure.